From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DB4B0ECAAD5 for ; Sat, 27 Aug 2022 10:39:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233542AbiH0Kjz (ORCPT ); Sat, 27 Aug 2022 06:39:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59050 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243326AbiH0Kjr (ORCPT ); Sat, 27 Aug 2022 06:39:47 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A47EC2FE for ; Sat, 27 Aug 2022 03:39:45 -0700 (PDT) Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4MFCm95yQQzkWcF; Sat, 27 Aug 2022 18:36:09 +0800 (CST) Received: from kwepemm600017.china.huawei.com (7.193.23.234) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Sat, 27 Aug 2022 18:39:44 +0800 Received: from [10.174.179.234] (10.174.179.234) by kwepemm600017.china.huawei.com (7.193.23.234) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Sat, 27 Aug 2022 18:39:42 +0800 Message-ID: Date: Sat, 27 Aug 2022 18:39:42 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: [PATCH -next v2 1/2] riscv: uaccess: rename __get/put_user_nocheck to __get/put_mem_nocheck To: Andrew Jones CC: Paul Walmsley , Palmer Dabbelt , Palmer Dabbelt , Albert Ou , , , , , Guohanjun References: <20220815032025.2685516-1-tongtiangen@huawei.com> <20220815032025.2685516-2-tongtiangen@huawei.com> <20220825105600.ezueddmwehob42rf@kamzik> <3541c980-7fcf-7047-cec7-3c2ca6381a99@huawei.com> <20220826074318.g6nwri5ziiutiio5@kamzik> From: Tong Tiangen In-Reply-To: <20220826074318.g6nwri5ziiutiio5@kamzik> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.179.234] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemm600017.china.huawei.com (7.193.23.234) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2022/8/26 15:43, Andrew Jones 写道: > On Fri, Aug 26, 2022 at 02:33:47PM +0800, Tong Tiangen wrote: >> >> >> 在 2022/8/25 18:56, Andrew Jones 写道: >>> On Mon, Aug 15, 2022 at 03:20:24AM +0000, Tong Tiangen wrote: >>>> Current, The helpers __get/put_user_nocheck() is used by get/put_user() and >>>> __get/put_kernel_nofault(), which is not always uaccess, so the name with >>>> *user* is not appropriate. >>>> >>>> Also rename xxx_user_xxx to xxx_mem_xx on the call path of >>>> __get/put_user_nocheck() >>>> >>>> Only refactor code without any functional changes. >>>> >>>> Signed-off-by: Tong Tiangen >>>> --- >>>> arch/riscv/include/asm/uaccess.h | 48 ++++++++++++++++---------------- >>>> 1 file changed, 24 insertions(+), 24 deletions(-) >>>> >>>> diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h >>>> index 855450bed9f5..1370da055b44 100644 >>>> --- a/arch/riscv/include/asm/uaccess.h >>>> +++ b/arch/riscv/include/asm/uaccess.h >>>> @@ -50,7 +50,7 @@ >>>> * call. >>>> */ >>>> -#define __get_user_asm(insn, x, ptr, err) \ >>>> +#define __get_mem_asm(insn, x, ptr, err) \ >>>> do { \ >>>> __typeof__(x) __x; \ >>>> __asm__ __volatile__ ( \ >>>> @@ -64,12 +64,12 @@ do { \ >>>> } while (0) >>>> #ifdef CONFIG_64BIT >>>> -#define __get_user_8(x, ptr, err) \ >>>> - __get_user_asm("ld", x, ptr, err) >>>> +#define __get_mem_8(x, ptr, err) \ >>>> + __get_mem_asm("ld", x, ptr, err) >>>> #else /* !CONFIG_64BIT */ >>>> -#define __get_user_8(x, ptr, err) \ >>>> +#define __get_mem_8(x, ptr, err) \ >>>> do { \ >>>> - u32 __user *__ptr = (u32 __user *)(ptr); \ >>>> + u32 *__ptr = (u32 *)(ptr); \ >>> >>> Doesn't casting away __user reduce sparse's utility? >> >> From the call logic[1], the address passed into this macro is not >> necessarily __user. I understand that no problem will be introduced for >> sparse's utility. >> >> In addition, there is no need to do a pointer conversion here, will be fixed >> next version. >> >> [1] __get_kernel_nofault -> __get_mem_nocheck -> __get_mem_8 > > Yes, I understood that. My concern was for the times that the address was > __user as we'd no longer get that check for them. Check __user ptr at __get_user() has the same effect? Is this understanding correct？ Thanks, Tong. > > Thanks, > drew > > .